Were you not able to get a handicap accessible room? Obviously that would be the best solution. IMO NCL does a fantastic job with their accommodations for disabilities.
Talk to NCL and see what they can do (prob depends on ship, cabin location). You may be able to keep the scooter at guest services, or talk to your cabin attendant. This has worked for my mom in the past when she was not able to get a ha cabin.
‘The other thing I’d note is to make sure you have a plan for embark and disembark. The scooter will be left in your cabin, and you just leave it there when you disembark, but then that person doesn’t have a scooter to use at the pier.
Disembark usually not too bad; you’ll be given a location to meet for disembark assistance and (eventually) somebody will wheel you off….but make sure guest services knows in advance.